Real-time monitoring of hybrid laser arc welding

激光焊接在从汽车到心脏起搏器等产品的自动化制造中发挥着重要作用，但缺陷可能导致组件故障，并可能造成灾难性后果。必须动用大量人力资源，以确保后处理的质素。通过采用新型高速在线诊断系统，我们可以在焊接过程中以微米级精度和高速（>300 kHz）实时测量焊缝熔深。该新技术，同轴相干成像，能够沿沿着焊接光束线成像，即使在存在强烈的光学后向散射。 信息从焊接区域本身获得，并且可以用于提供反馈以关闭控制回路，从而允许期望的焊接性能而无需用户干预，从而减少对后分析测试的需要（并且显著减少人力需求），同时提高焊接质量。潜在的甚至更重要的后果，在线相干成像系统可以允许一种新的焊接范例-混合激光弧焊-被广泛采用。这种新的焊接技术（被称为“一代人中最具破坏性的”）将激光束焊接的穿透深度和低热输入与电弧焊接的高效率相结合，但潜在客户告诉我们，穿透深度的不确定性减缓了许多细分市场的采用。实时深度测量系统可以帮助认证各种行业的混合激光弧焊，包括石油化工，核能和国防。NSERC I2 I的资助将使我们能够开发一种便携式在线相干成像系统，适合与商业焊接系统集成。使用专用硬件控制器的高速数字处理将允许实时反馈以闭合控制回路。在一家焊接公司应用实验室的成功演示将被用来吸引一家加拿大公司生产最终的商业产品（基于我们的原型），并将其出售给世界各地的最终用户。

Laser welding plays an important role in the automated manufacturing of products ranging from cars to pacemakers, but defects can lead to component failure with potentially catastrophic results. Considerable manpower resources must be employed for post-processing quality assurance. By incorporating a novel high speed inline diagnostic system, we can measure weld penetration depth on-the-fly during the welding process with micron precision and at high speeds (>300 kHz). The novel technique, inline coherent imaging, is able to image along the welding beam line, even in the presence of intense optical backscatter. Information is obtained from the welding region itself and can be used to provide feedback to close the control loop to allow desired welding performance with no user intervention, thus reducing the need for post-analysis testing (and dramatically reducing manpower requirements) while improving weld quality. Of potentially even more important consequence, the inline coherent imaging system may allow a new paradigm of welding - hybrid laser arc welding - to be broadly adopted. This new welding technique (described as "the most disruptive in a generation") combines the depth of penetration and low heat input of laser beam welding with the high efficiency of arc welding, but potential clients tell us that uncertainty about penetration depth have slowed adoption in many market segments. A real-time depth measurement system could help certification of hybrid laser arc welding for a variety of industries including petro-chemical, nuclear and defense. NSERC I2I funding will allow us to develop a portable inline coherent imaging system appropriate for integration with commercial welding systems. High-speed digital processing using a dedicated hardware controller will allow real-time feedback to close the control loop. Successful demonstration in a welding company applications laboratory will be used to attract a Canadian company to produce the final commercial product (based on our prototype) and sell it to end users around the world.